Engine DAEWOO LACETTI 2004 Service Repair Manual

7B – 34IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
COMPRESSOR
Removal Procedure
1. Disconnect the negative battery cable.
2. Discharge and recover the refrigerant. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System” in this section.
3. Remove the discharge hose mounting nut.
4. Lift the discharge hose mounting block and the suc-
tion hose from the compressor.
5. Raise and suitably support the vehicle.
6. Remove the engine under cover. Refer to Section
9N, Frame and Underbody.
7. Remove the accessory drive belt.
8. Disconnect the electrical connector at the compres-
sor.
9. Remove the compressor–to–bracket bolts. (1.4
DOHC shown, others similar)
10. Remove the compressor.
11. Drain the oil from the compressor into a container.
Measure the amount of the oil that is drained. Then
discard the used oil.
Installation Procedure
1. Add oil to the new compressor. Use the exact
amount of oil that you drained from the old com-
pressor.
2. Install the compressor.
3. Install the compressor–to–bracket mounting bolts.
Tighten
(1.4 DOHC, 1.6 DOHC only)
Tighten the upper compressor–to–bracket mounting
bolts(M8) to 25 NSm (18 lb–ft).
Tighten the lower compressor–to–bracket mounting
bolts(M10) to 45 NSm (33 lb–ft).

MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 35
DAEWOO V–121 BL4
Tighten
(1.8 DOHC, 2.0 DOHC only)
Tighten the front compressor–to–bracket mounting
bolts to 35 NSm (26 lb–ft).
Tighten the rear compressor–to–bracket mounting
bolts to 20 NSm (15 lb–ft).
4. Install new sealing washers to the suction hose and
the discharge hose mounting.
5. Connect the electrical connector at the compressor.
6. Install the accessory drive belt.
7. Install the engine under cover. Refer to Section 9N,
Frame and Underbody.
8. Lower the vehicle.
9. Place the suction hose into its cavity in the com-
pressor and install the discharge hose mounting
block to clamp it into place. Hold this all together
while tightening the retaining nut.
Tighten
Tighten the refrigerant discharge hose block–to–
compressor retaining nut to 33 NSm (24 lb–ft).
10. Connect the negative battery cable.
11. Evacuate and recharge the A/C system. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System” in this section.
CONDENSER
Removal Procedure
1. Disconnect the negative battery cable.
2. Discharge and recover the refrigerant. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System”in this section.
3. Remove the front bumper. Refer to Section 9O,
Bumpers and Fascias.
4. Remove the discharge hose block–to–condenser
retaining nut.
5. Remove the discharge hose from the condenser.
6. Remove the liquid pipe block–to–receiver–dryer
cretaining nut.
7. Remove the liquid pipe from the receiver–dryer.

MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 51
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
GENERAL INFORMATION
THE V5 A/C SYSTEM
The V5 variable displacement compressor along with the
thermal expansion valve on the evaporator, constitutes a
largely self–regulating system. There is no pressure cycl-
ing switch, no high–pressure cut–off switch and no low–
pressure cut–off switch. The compressor clutch is con-
trolled by the electronic control module (ECM), which
receives data from various engine systems and from a
pressure transducer located in the high–pressure refriger-
ant pipe. In normal operation, the clutch is engaged contin-
uously. Should one of the monitored conditions become
abnormal, the ECM will disengage the compressor clutch
until normal operation is restored. These conditions in-
clude the following:
S Wide–open throttle.
S High engine coolant temperature.
S High engine RPM.
S Refrigerant low pressure.
S Refrigerant high pressure.
The compressor clutch will remain disengaged until nor-
mal operation is established.
SYSTEM
COMPONENTS–FUNCTIONAL
Compressor
All compressors are belt–driven from the engine crank-
shaft through the compressor clutch pulley. The compres-
sor pulley rotates without driving the compressor shaft un-
til an electromagnetic clutch coil is energized. When
voltage is applied to energize the clutch coil, the clutch
plate and hub assembly is drawn rearward toward the
pulley. The magnetic force locks the clutch plate and
pulley together as one unit to drive the compressor shaft.
As the compressor shaft is driven, it compresses the low–
pressure refrigerant vapor from the evaporator into a
high–pressure, high–temperature vapor. The refrigerant
oil which is used to lubricate the compressor is carried with
the refrigerant. Refer to ”V5 Air Conditioning Compressor
Overhaul” in this section.
Condenser Core
The condenser assembly in front of the radiator consists
of coils which carry the refrigerant, and cooling fins that
provide the rapid transfer of heat. The air passing through
the condenser cools the high–pressure refrigerant vapor
and causes it to condense into a liquid.
Expansion Valve
The expansion valve is located with the evaporator core,
on the front passenger side fire wall.
The expansion valve can fail in three different positions:
open, closed, or restricted.
An expansion valve that fails in the open position will result
in a noisy A/C compressor or no cooling. The cause can
be a broken spring, a broken ball, or excessive moisture
in the A/C system. If the spring or the ball are found to be
defective, replace the expansion valve. If excessive mois-
ture is found in the A/C system, recycle the refrigerant.
An expansion valve that fails in the closed position will re-
sult in low suction pressure and no cooling. This may be
caused by a failed power dome or excessive moisture in
the A/C system. If the power dome on the expansion valve
is found to be defective, replace the expansion valve. If ex-
cessive moisture is found in the A/C system, recycle the
refrigerant.
A restricted expansion valve will result in low suction pres-
sure and no cooling. This may be caused by debris in the
refrigerant system. If debris is believed to be the cause, re-
cycle the refrigerant, replace the expansion valve, and re-
place the receiver–dryer.
Evaporator Core
The evaporator is a device which cools and dehumidifies
the air before it enters the vehicle. High–pressure liquid re-
frigerant flows through the expansion tube orifice and be-
comes a low–pressure gas in the evaporator. The heat in
the air passing through the evaporator core is transferred
to the cooler surface of the core, which cools the air. As the
process of heat transfer from the air to the evaporator core
surface is taking place, any moisture or humidity in the air
condenses on the outside surface of the evaporator core
and is drained off as water.
Receiver–Dryer
The sealed receiver–dryer assembly is connected to the
condenser outlet pipe. It acts as a refrigerant storing con-
tainer, receiving liquid, vapor, and refrigerant oil from the
evaporator.
At the bottom of the receiver–dryer is the desiccant, which
acts as a drying agent for the moisture that may have en-
tered the system. An oil bleed hole is located near the bot-
tom of the receiver–dryer outlet pipe to provide an oil re-
turn path to the compressor. The receiver–dryer is
serviceable only as an assembly.
Heater Core
The heater core heats the air before it enters the vehicle.
Engine coolant is circulated through the core to heat the
outside air passing over the fins of the core. The core is
functional at all times and may be used to temper condi-
tioned air in the A/C mode as well as in the heat or the vent
modes.

7B – 52IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
SYSTEM COMPONENTS–CONTROL
Controller
The operation of the A/C system is controlled by the
switches and the lever on the control head. The compres-
sor clutch and the blower are connected electrically to the
control head by a wiring harness. The blower circuit is
open in the OFF mode. Airflow is provided by the four
blower speeds available in the remaining modes. Cooled
and dehumidified air is available in the MAX, NORMAL,
BI–LEVEL, and DEFROST modes.
The temperature is controlled by the position of the tem-
perature knob on the control head. A cable connects this
knob to the temperature door, which controls the airflow
through the heater core. As the temperature knob is
moved through its range of travel, a sliding clip on the
cable at the temperature valve connection should assume
a position ensuring that the temperature door will seat in
both extreme positions. The temperature door position is
independent of the mode control switch. The temperature
door on some models is controlled electrically, eliminating
the need for the temperature cable.
The electric engine cooling fan on some vehicles is not
part of the A/C control system; however, the fan is opera-
tional any time the A/C control is in the MAX, NORMAL,
or BI–LEVEL modes. Some models provide for engine
cooling fan operation when the controller is in the DE-
FROST mode. This added feature is part of the A/C con-
troller function and is aimed at preventing excessive com-
pressor head temperatures. It also allows the A/C system
to function more efficiently. On some models, the engine
cooling fan will be turned off during road speed conditions
above 56 km/h (35 mph), when the airflow though the con-
denser coil is adequate for efficient cooling. The operation
of the cooling fan is controlled by the powertrain control
module (PCM), or the engine control module (ECM),
through the cooling fan relay.
Pressure Transducer
The pressure transducer incorporates the functions of the
high–pressure and the low–pressure cutout switches
along with the fan cycling switch. The pressure transducer
is located in the high–side liquid refrigerant line near the
right front strut tower and the air filter assembly.
Wide–Open Throttle (WOT) Compressor
Cutoff
During full throttle acceleration on vehicles equipped with
multi–port injection (MPI), the throttle position sensor
(TPS) sends a signal to the PCM or the ECM, which then
controls the compressor clutch.
A/C Time Delay Relay
This relay on some vehicles controls the current to the en-
tire A/C system and provides a short delay of A/C opera-
tion upon start–up.
V5 COMPRESSOR–GENERAL
DESCRIPTION
Different vehicles with V5 compressors may exhibit differ-
ences in mounting and installation, but overhaul proce-
dures are similar.
Before removing the compressor or performing on–ve-
hicle repairs, clean the compressor connections and the
outside of the compressor.
Important : After removing a compressor from the vehicle
for servicing, drain the oil by removing the oil drain plug.
Also drain the oil from the suction and the discharge ports
to insure complete draining. Measure the amount of oil
drained, and record that amount. Discard the used oil and
add the same amount of new polyalkaline glycol (PAG) re-
frigerant oil to the compressor.
The compressor has been removed from the vehicle un-
less otherwise indicated.
Clean tools and a clean work area are important for proper
servicing. Keep dirt and foreign material from getting on or
into the compressor parts. Parts that are to be reassem-
bled should be cleaned with trichloroethane, naphtha,
stoddard solvent, kerosene, or equivalent solvents. Dry
the cleaned parts with clean dry air. Use only lint–free
cloths to wipe the parts.
V5 COMPRESSOR–DESCRIPTION OF
OPERATION
The V5 is a variable displacement compressor that can
match the automotive air conditioning (A/C) demand un-
der all conditions without cycling. The basic compressor
mechanism is a variable angle wobble–plate with five ax-
ially oriented cylinders. The center of control of the com-
pressor displacement is a bellows–actuated control valve
located in the rear head of the compressor. The control
valve senses compressor suction pressure.
The wobble–plate angle and the compressor displace-
ment are controlled by the crankcase suction pressure dif-
ferential. When the A/C capacity demand is high, the suc-
tion pressure will be above the control point. The valve will
maintain a bleed from crankcase to suction. With no
crankcase suction pressure differential, the compressor
will have maximum displacement.
When the A/C capacity demand is lower and the suction
pressure reaches the control point, the valve will bleed dis-
charge gas into the crankcase and close off a passage
from the crankcase to the suction plenum. The angle of the
wobble–plate is controlled by a force balance on the five
pistons. A slight elevation of the crankcase suction pres-
sure differential creates total force on the pistons resulting
in a movement about the wobbleplate pivot pin that re-
duces the plate angle.
The compressor has a unique lubrication system. The
crankcase suction bleed is routed through the rotating
wobble–plate for lubrication of the wobble–plate bearing.
The rotation acts as an oil separator which removes some

7D – 8IAUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
NO HOT AIR FROM BLOWER
StepActionValue(s)YesNo
1Check the coolant level.
Is the coolant level correct?–Go to Step 3Go to Step 2
2Add coolant as needed.
Is the heater operating?–System OKGo to Step 3
31. Turn the ignition to ON.
2. Observe the temperature indication screen of
the controller.
Does the digit flash on and off?–Go to Step 4Go to Step 5
4Run a self–diagnosis circuit check.
Does the display indicate a defect code?–Go to the table
for the code
that flashesGo to Step 7
5Observe the blower motor operation.
Is the blower motor functioning at all?–Go to Step 6Go to ”Blower
Motor Does
Not Run at All”
6Use the blower push switch to cycle the blower
through its different speeds.
Does the motor function at different speeds?–Go to Step 7Go to ”Code 6
– Power Tran-
sistor Error”
71. Run the blower and operate the MODE push
switch manually.
2. Check for airflow out the various outlets.
Does the air flow from the different outlets as it
should?–Go to Step 9Go to Step 8
81. Remove the heater outlet and check for ob-
structions.
2. Remove any obstructions found.
Is the heater operating?–System OKGo to Step 9
9Observe the air mix door (AMD) motor while chang-
ing the temperature setting from 18 to 32°C (64 to
90°F) and then from 32 to 18°C (90 to 64°F).
Is the AMD motor functioning properly?–Go to Step 10Go to”Code 4 –
Air Mix Door
Error”
10Check the coolant hoses for leaks or kinks.
Are the coolant hoses in good condition?–Go to Step 12Go to Step 11
11Repair any problem with the coolant hoses.
Is the heater operating?–System OKGo to Step 12
12Check the surge tank cap.
Is the surge tank cap in good condition?–Go to Step 14Go to Step 13
13Repair or replace the surge tank cap as needed.
Is the heater operating?–System OKGo to Step 14
141. Set the A/C switch to OFF.
2. Set the temperature control to 32°C (90°F).
3. Set the blower motor speed to full high (all seg-
ments illuminated on the display).
4. Remove the surge tank cap.
5. Start the vehicle and run the engine at idle.
6. Watch for the flow of the coolant when the ther-
mostat opens.
Does the coolant flow?–Go to Step 16Go to Step 15

7D – 12IAUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
BLOWER MOTOR DOES NOT RUN AT ALL
StepActionValue(s)YesNo
11. Turn the ignition to ON.
2. Observe the temperature indication screen of
the controller.
Does the digit go on and off?–Go to Step 2Go to Step 3
2Run a self–diagnosis circuit check.
Does the display indicate a defect code?–Go to the table
for the code
that flashes.–
3Check fuse F7 in the I/P fuse block.
Is this fuse in good condition?–Go to Step 5Go to Step 4
4Replace fuse F7.
Is the repair complete?–System OK–
5Check fuse EF3 in the engine fuse block.
Is this fuse in good condition?–Go to Step 7Go to Step 6
6Replace fuse EF3.
Is the repair complete?–System OK–
71. Turn the ignition switch to ON.
2. Measure the voltage between ground and ter-
minal 87(Violet) of the blower relay.
Is the voltage within the specified value?11–14 vGo to Step 15Go to Step 8
8Measure the voltage between ground and terminal
86 (Brown) at the blower relay.
Is the voltage within the specified value?11–14 vGo to Step 10Go to Step 9

AUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM 7D – 13
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
91. Turn the ignition switch to OFF.
2. Check circuit (Brown) between terminal 86 of
the blower relay to F7 in the I/P fuse block.
3. Repair any problem found in the wiring or ter-
minals at the relay socket or connector C203.
Is the repair complete?–System OK–
10Measure the voltage between ground and terminal
30 (Red) at the blower relay.
Is the voltage within the specified value?11–14 vGo to Step 12Go to Step 11
111. Turn the ignition switch to OFF.
2. Check circuit (Red) between terminal 30 of the
blower relay to EF3 in the engine fuse block.
3. Repair any problem found in the wiring or ter-
minals at the fuse block connector C105, con-
nector C202, or at the relay socket.
Is the repair complete?–System OK–
121. Turn the ignition switch to OFF.
2. Check the continuity in the wiring harness be-
tween the blower relay terminal 85 (Black) and
ground.
Does the ohmmeter show the specified value?
0 ΩGo to Step 14Go to Step 13
13Repair any problem found in terminal 85 at the relay
connector, circuit (Black), Connector C201, or
ground G201.
Is the repair complete?–System OK–
14Replace the blower relay.
Is the repair complete?–System OK–
151. Turn the ignition switch to OFF.
2. Disconnect the wiring harness at the blower
motor.
3. Turn the ignition switch to ON.
4. Measure voltage between ground and blower
connector 1 (Yellow).
Is the voltage within the specified value?11–14 vGo to Step 17Go to Step 16
161. Turn the ignition switch to OFF.
2. Check circuit (Yellow) between blower connec-
tor terminal 1 and blower relay terminal 87.
3. Repair any problem found in the wiring or a
connector terminal at the blower connector,
connector C208, or the blower relay socket.
Is the repair complete?–System OK–
17Measure the resistance between the connector ter-
minals on the blower motor.
Does the resistance match the specified value?
5 ΩGo to Step 19Go to Step 18
18Replace the blower motor.
Is the repair complete?–System OK–
19Measure the resistance of circuit (Violet) between
terminal 2 of the blower connector and terminal 30
of the Max HI relay and terminal 6 of the power tran-
sistor.
Does the resistance match the specified value?
0 ΩGo to Step 21Go to Step 20

7D – 40IAUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
GENERAL INFORMATION
THE V5 SYSTEM
Refer to Section 7B, Manual Control Heating, Ventilation,
and Air Conditioning System,for general information de-
tails for the following:
S System Components – Functional.
S The V5 A/C System.
S V5 Compressor – Description of Operation.
S V5 Compressor – General Description.
SYSTEM COMPONENTS–CONTROL
Controller
The operation of the A/C system is controlled by the
switches on the control head. This console–mounted
heating and ventilation system contains the following
knobs and display:
Temperature Control Push Knobs
1. Raise the temperature of the air entering the ve-
hicle by pressing the top switch, with the red arrow
pointing upward.
2. Lower the temperature by pressing the bottom
switch, with the blue arrow pointing downward.
3. Actuate the air mix door by an electric motor.
4. Vary the mix of the air passing through the heater
core with the air bypassing the core.
Each press of a switch changes the set temperature by in-
crements of 0.5°C (1°F). This is shown in the temperature
window on the function display.
The Function Display
This is an LCD display indicating the status of the control
settings selected. Starting from the left end of the display,
the sections are as follows:
1. Temperature setting – Indicates the temperature set
with the temperature control knob.
2. Auto status – Indicates whether the system is oper-
ating in the full auto mode or the manual mode.
3. Defroster icon – Indicates manual selection of full
defrost mode.
4. Mode – Indicated by icon, the mode chosen by the
system in auto (or by the operator in manual) is
shown by an illumination arrow indicating the air
path.
5. A/C – A snowflake icon indicating whether the A/C
is ON or OFF.
6. Fan speed – Indicates the fan speed by illuminating
a bar based on the segment at the front, for low
speed, and adding additional segments in order up
to the fifth, for high speed.Eight Additional Push Knobs
1. Full defrost – Causes the mode motors to direct all
air to the windshield and aide window outlets for
maximum defrosting.
2. Air intake – Switches between fresh air intake, the
default, and recirculating air. Airflow arrows on the
display indicate the mode in effect.
3. Full Auto Switch – Maintains the set temperature
automatically. In this mode, the fully automatic tem-
perature control (FATC) system controls the follow-
ing:
S The air mix door motor.
S The mode door motor.
S The blower motor speed.
S The inlet air door motor.
S A/C ON/OFF.
4. OFF Switch – Turns the automatic air conditioning
and fan control off.
5. Mode Switch – Allows manual selection of the air-
flow direction.
S Selection is shown on the function display.
S Each time the mode switch is pressed, the next
function is displayed.
6. A/C Switch – Allows manual selection and control
of the air conditioning function.
7. Fan Control Switch – Allows manual selection
among five fan speeds.
8. Defogger Switch – Turns on the electric defogging
heater in the rear window and the outside rearview
mirrors, if the vehicle is equipped with heated mir-
rors.
Pressure Transducer
Pressure transducer switching incorporates the functions
of the high–pressure and the low–pressure cutout
switches along with the fan cycling switch. The pressure
transducer is located in the high–side liquid refrigerant line
behind the right strut tower, between the right strut tower
and the fire wall. The output from this pressure transducer
goes to the electronic control module (ECM), which con-
trols the compressor function based on the pressure sig-
nal.
Wide–Open Throttle (WOT) Compressor
Cutoff
During full–throttle acceleration, the throttle position sen-
sor (TPS) sends a signal to the ECM, which then controls
the compressor clutch.
High RPM Cutoff
As engine rpm approaches the maximum limit, the ECM
will disengage the compressor clutch until the engine
slows to a lower rpm.

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 45
DAEWOO V–121 BL4
DTC 23
Battery Voltage High
CAUTION : The sensing and diagnostic module(SDM)
can maintain sufficient voltage to deploy the airbags
and pretensioners for 1 minute after the ignition is
OFF and the fuse has been removed. If the airbags
and pretensioners are not disconnected, do not be-
gin service until one minute has passed after discon-
necting power to SDM. Otherwise, injury could result.
CAUTION : During service procedure, be very careful
when handling the SDM. Never strike or jar the SDM.Never power the supplemental inflatable re-
straints(SIR) when the SDM is not rigidly attached to
the vehicle. All SDM mounting bolts must be carefully
tightened , and the arrow on the SDM must be point
toward the front of the vehicle to ensure proper op-
eration of the SIR. The SDM could be activated if it is
powered when it is not rigidly attached to the vehicle,
resulting in unexpected deployment and possible in-
jury.
Step
ActionValue(s)YesNo
1Check the vehicle’s charging system including alter-
nator. Refer toSection 1E, Engine Electrical.
Is the charging system OK?–Go to Step 3Go to Step 2
2Repair the charging system.
Is the repair completed?–Check the sys-
tem again.–
31. Disconnect the negative battery cable.
2. Replace the SDM. Is the repair completed?–Check the sys-
tem again.–

SECTION : 9A
BODY WIRING SYSTEM
CAUTION : Disconnect the negative battery cable before removing or installing any electrical unit or when a tool
or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help
prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise noted.
TABLE OF CONTENTS
SCHEMATIC AND ROUTING DIAGRAMS9A–1 . . . . .
Wire Color Chart 9A–1. . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Distribution Schematic 9A–3. . . . . . . . . . . . . . .
Fuse Block Locator (Engine) 9A–12. . . . . . . . . . . . . . .
Fuse Block Locator (Passenger Compartment) 9A–12
Fuse Chart 9A–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front Harness Routing 9A–15. . . . . . . . . . . . . . . . . . . .
Rear Harness Routing 9A–16. . . . . . . . . . . . . . . . . . . . .
Hatchback Rear Harness Routing 9A–17. . . . . . . . . . .
Floor Harness Routing 9A–18. . . . . . . . . . . . . . . . . . . .
Instrument Harness Routing 9A–19. . . . . . . . . . . . . . . .
Door Harness Routing 9A–20. . . . . . . . . . . . . . . . . . . . .
SCHEMATIC AND ROUTING DIAGRAMS
WIRE COLOR CHART
Wire ColorAbbreviation On Schematic
GreenDK GRN
Light GreenLT GRN
BlueDK BLU
BrownBRN
OrangeORN
YellowYEL
GreyGRY
Sky BlueLT BLU
RedRED
BlackBLK
PinkPNK
WhiteWHT
PurplePPL